article: Do you kow that animals have love for each other and their children just like us humans? Let me tell you some moving stories of great animal parents.
  Several years ago a heavy rain hit a town and made the river go up. When the rain stopped, people found that a dog swam to an island in the river twice a day for two weeks. Why did she do so? Her four children were there. The mother swam there every day to feed her babies. This true story moved many people.
  Another story is about chimpanzees . A scientist named Jane Goodall spent 4 years living with chimpanzees in Africa. She found that chimpanzees also cared for those that were hurt or got lost. "It is not only humans who have duties, animals also do," she said.
  Two birds in Chengdu also showed their parental  love. Their baby was hurt and fell on the street in the center of the city. Cars were driving past but the brave parents rushed down to the road and took the little bird away with their claws .
question: The two birds rushed down and took the little one away because   _  .
options: they didn't like their baby they were not kind enough they wanted to teach their baby they wanted to save their baby